An example of a plant for the aerobic treatment of organic wastes is disclosed in GB 1 381 848. Said plant, that comprises an enclosed room, having a ventilating support surface on which waste heaps are placed, uses a blower for sucking or blowing air through the heaps. That solution is limited from the operating standpoint, in that the blower, unless its rotation direction is reversed, can only operate by sucking or blowing air in the same direction.
Another exemplary plant for the aerobic treatment of organic wastes is disclosed in European Patent No. EP 1 431 262, in the name of the same Applicant.
Such a plant, housed within an enclosed building, has a ventilated paving or floor on which heaps of organic wastes are deposited, the aerobic treatment of said organic wastes taking place through a phase of fermentation/bio-oxidation performed by means of forced air. Said plant further includes means for generating an alternating air flow in two opposite directions, through said paving and said heaps, which means preferably consist of fans, pairs of three-way valves and by-passes for reversing in continuous manner the air flow generated by said fans.
A drawback of the above solution is its construction and management complexity, resulting in a non-negligible resource burden: indeed, a rather complex circuit is to be provided where each valve requires a dedicated actuator, what makes the system very onerous.
The above solution is moreover limited from the operating standpoint, in that each assembly formed by a fan, valves and by-passes can only operate either by sucking used-up air from the room containing the organic wastes in order to exhaust that air to the outside, or by sucking fresh air from the outside to blow it into the room containing said organic wastes.
Systems for reversing the direction of a gas flow without stopping or changing the fan rotation direction are also known, e.g. from U.S. Pat. No. 1,959,106, said systems operating thanks to a set of stationary propellers and partitions that are axially moved as an integral unit by means of a single actuator, whereby the gas flow can simultaneously flow according two opposite directions.